George Osborne has sent an unequivocal message that Conservatives have to work harder to reach out beyond traditional voters by hiring a leading thinktank boss who has warned that the party is still seen as the champion of the rich.

Neil O'Brien, the director of the centre-right Policy Exchange and who grew up in Huddersfield, is to offer the chancellor policy advice across the political landscape with a particular focus on how to reach voters in the north of England. His work will feed into the Tory manifesto for the 2015 general election.

The appointment of O'Brien, a moderniser who first made his name as director of the Open Europe thinktank, was welcomed across the Conservative party. Tim Montgomerie, founder of the ConservativeHome website who has called on the leadership not to lose sight of traditional values, blogged: "This is a big loss to PX [Policy Exchange] but a big boost to No 11. O'Brien has been wooed for some time by the Tories and they've finally got their man."

But O'Brien has a radically different vision to that outlined by Conservative Voice, the new group supported by Montgomerie, which has criticised the "almost evangelical focus on the 'modernisation' or 'detoxification' of the Conservative brand". In a Guardian article in October, O'Brien directly challenged the new group when he wrote: "Obviously Cameron should ignore calls from the usual suspects to lurch rightward."

Osborne is said to have been impressed by O'Brien's call for a greater focus on winning black and minority ethnic, blue-collar and northern voters. He said the government should do this by launching a "war on unemployment" by increasing working tax credits and by cutting employers' national insurance contributions for people on low wages. He also wrote that the Tories are "still seen as the party of the rich".

Conservative Voice will say that it wholeheartedly agrees with O'Brien in these areas because the new group was set up to attract aspirational voters. But Tories on the right will be less keen on O'Brien's support for gay marriage, a view supported by Osborne who is one of the most socially liberal MPs in any party.

O'Brien strongly supports the government's welfare reform programme. But he believes that the government needs to do more to encourage people into work and should bear in mind that demonising the unemployed will revive memories of what Theresa May called the "nasty party".

O'Brien showed that reaching out to voters in the north will be a key priority in an article in this week's Spectator in which he argues that Westminster's main parties have abandoned the north. He writes: "David Cameron inherited lots of political baggage from the 1980s which makes it tough for the Tories to win a hearing in northern cities. The Liberal Democrats used to run in the north of England in opposition to complacent Labour councils. Now they are trying to avoid being minced for joining the coalition. And after the recession and the debt crisis Gordon Brown left behind, northerners don't feel so enthusiastic about Labour either."